1. Field of the Invention
The present invention generally relates to cooling systems. More specifically, the present invention is directed to the detection of faulty central processing unit (CPU) heat sink coupling during system power-up.
2. Related Art
With the increase in heat dissipation and the reduction in overall form factors, thermal management of CPUs and other types of integrated circuits has become an increasingly important element of electronic product design.
Heat sinks are devices that enhance heat dissipation from a hot surface, usually the packaging of a heat generating component such as a CPU or other integrated circuit, to a cooling fluid, usually air. Heat sinks typically include a large number of fins to increase the surface area that is in direct contact with air. This allows more heat to be dissipated to control the component operating temperature. Some newer heat sinks also include vapor chambers that are configured to use an internal liquid-to-vapor phase change to spread heat efficiently to air-cooled fins.
The surface of a CPU or heat sink is never entirely flat; if a heat sink is placed directly on a CPU, there will be tiny air gaps between the two. Since air conducts heat poorly, these gaps have a negative effect on heat transfer to the heat sink. Therefore, a heat sink compound with a high thermal conductivity is generally used to fill these gaps, and thus improve heat conductivity between the CPU and heat sink.
In some cases, the heat sink compound must be precisely applied during the attachment of a heat sink to a CPU, and cannot be applied in the field. As such, if the heat sink is removed from the CPU and the heat sink compound is the least bit disturbed, a new heat sink must be supplied, increasing the duration of repair.
A faulty or improperly mounted heat sink will not sufficiently cool a CPU and will likely result in the overheating of the CPU at the most inopportune time. There is a need, therefore, for a technique for predicting this type of fault prior to the overheating of a CPU.